The House of Representatives is expected today to make a second attempt to override President Bush's veto of an expansion of the Children's Health Insurance Program, and advocates for it are appropriately putting pressure on a number of Republicans.

Two groups, Americans United for Change and USAction, have targeted 50 House members, singling out freshmen and those expecting tough re-election battles in the hope that they won't want a record against health care for children on their resumes.

That kind of threat won't work on Rep. John Peterson, the Venango County Republican who voted against a $35 billion, five-year CHIP expansion that could bring 4 million more children into the program. That's because Mr. Peterson already has announced he won't seek re-election to the office he has held since 1997.

But there are more than 7,000 reasons for Mr. Peterson to change his earlier votes. They are the children in his district who don't have health insurance coverage, youngsters who could be helped by a CHIP expansion.

As Mr. Peterson pointed out in a piece he wrote for this newspaper, "increasing access to quality, affordable health care for our rural communities has been the hallmark" of his 30 years in elected office, counting Congress and the state Legislature. He noted that he was instrumental in formulating Pennsylvania's original CHIP law and was named 2006 Legislator of the Year by the National Organization of State Offices of Rural Health.

Mr. Peterson now has an opportunity to improve on that legacy by opening the access to affordable health- care coverage wide enough to let in all of Pennsylvania's and America's children who need it.